Here, Gualdrini et al. found that loss of H3K9me3 caused by SETDB1 depletion was associated with increased recruitment of CTCF to >1600 DNA binding motifs contained within SINE B2 repeats, a previously unidentified target of SETDB1-mediated repression. Their findings suggest a role for H3K9me3 in restraining genomic distribution and activity of CTCF, influencing chromatin organization and gene regulation.